Trailer hitch and brake-actuating means



Sept. 27, w49. e. swAlN 2,483,074

TRAILER HITCH AND BRAKE-ACTUATING MEANS Filed Nov. 7, 1945 5 Shee'ts-Sheet 1 h5 K @gw w Sept, 27, i949. G, swA|N 2,483,074

TRAILER HITCH AND BRAKE-ACTUATING MEANSI 'lll 5 Sheets-Sheet 3 G. SWAIN TRAILER HITCH AND BRAKE-ACTUATING MEANS sept. 27, A1949.

Filed Nov. 7, 1945 Gurdon Swain Sept. 27, 1949.

G. swAlNy TRAILER HITCH AND BRAKE-ACTUTING MEANS Filed NOV. 7, 1945 5 Sheets-Sheet 4 Gurdon Swain v K///////w`/////////////// NK 9W Sept. 27, i949. G. swAlN TRAILER HITQH AND BRAKE-ACTUTING MEANS 5 Sheets-Sheet l5 Filed Nov. 7, 1945 www l 3mm IMHI Patented Sept. 27, 1949 buiten STAT Gurdon Swain, Houston, Tex.

Application November '7, 1945, Serial No. 627,112

11 Claims.

The invention relates to hitches and brakeactuators for trailers of various types, in which forward movement of the trailer with respect to a passenger automobile, truck, tractor, or other towing vehicle, when the latter is reduced in speed, causes application of the trailer brakes.

One object ofthe invention is to provide a reliable vmechanism ofI the type set `iorth in which there canv be no sudden jerking of the relatively slidable parts lconnected with the towing vehicle and the trailer respectively, such jerking being prohibited by the effective association of shockabsorbing means (preferably hydraulic) with, said relatively slidable members.

Another object of the invention is to provide a construction which is equally applicable for applying hydraulic brakes or mechanical brakes.

A further object of the invention is the provision of a novel construction in which all movable parts are confinedwithin adequate housing means to protectthem againstroad or other haaards. v

Yet another object' is to provide Va novel relation`of elements which vwhile including` all necessary mechanism, will ybe compact and free from portions projecting objectionably.

Still further objects are to provide unique chocking means to prevent relative sliding of the part-s connected with the towing vehicle and trailer respectively, when said towing vehicle and l trailerare to be backed, thus preventing the application of the trailer brakesduring such backing, and to provide a quickly and easilyapplicable and releasable means for coupling the invention to the towing vehicle and locking them against :i:

accidental release. y

With the foregoing and minor objects in view, the invention resides in the novel construction and relation of elements hereinafter described Yand claimed, and shown in the accompanying drawings. l

Figures l and la jointly disclose a longitudinal sectional View, partly in elevation showing the invention associated with a trailer tongue, the coupling means'beingvreleased and the various other parts shown in towing position.

Figs. 2 and2a jointly disclose a longitudinal sectional view showing lthe coupling means applied and illustrating the relatively movable parts in maximum brake-applying position.

Figs. 3 and 3a, jointly disclose a horizontal sectional view as indicated by the line 3-3a` of Figs. 1 and 1a.

Figs. 4 and 5 are transverse sectional views on vlines 4-4 and 5--5 of Fig. 1.

(Cl. 18S-112) Figs. 6 and 7 are transverse sectionalviews on lines 6-6 and 'I-'I of Fig. 1a.

Fig. 8 is a top plan y,View showing the forwardly and rearwardly movable unit which is slidable within the trailer tongue and is connected at its front end with the towing vehicle.

Fig. 9 is a side elevation showing a form of plunger for the shock-absorbing means, different from the plunger shown in preceding views.

Fig. 10 is a detail section on line Ill- I of Fig. 9.

Fig. 11 is a side elevation showing a second form of the invention used for connecting a house trailer to a towing vehicle.

Fig. 12 is an enlarged fragmentary elevation partly broken away and in section, showing the construction illustrated in dotted lines in Fig. 11.

Fig. 13 is a side elevation showing another form of the invention used for connecting a trailer with a truck.

Fig. 14 is a top'view of a portion of the trailer frame shown in Fig. 13.

The construction disclosed in Figs. 1 to l0 of the drawings will iirst be explained, and while that construction will be speciiically described, attention is invited to the possibility of making variations within the scope of the invention as claimed.

A trailer tongue is disclosed comprising a hollow front section I2 having a closed front end I3, a rear hollow section I4 bolted or otherwise secured at I5 to the trailer frame it, and a shockabsorbing cylinder Il interposed between said sections I2 and I4 and rigidly secured thereto. Flange and bolt connections I8 may well be emplofeldI between these three tongue sections I2, I4 an A front carriage I9 is slidably mounted in the front tongue section i2 and is provided at its front end with coupling means 2@ for connecting it 'th a ball 2| on a tow bar 22 or other desired portion of a towing vehicle, said carriage I9 preferably having rollers 23 engaging the front tongue section I2.

A rear carriage 24 is slidably mounted in the rear tongue section ldgsaid carriage 2 having rollers 25 engaging said tongue section I4. This carriage 2li is provided with a forwardly projecting plunger 26, the front portion of which is operable in the shock-absorbing cylinder Il to prevent any sudden iorward or rearward jerks of said carriage with respect to the trailer tongue, thus prohibiting too-sudden application o f trailer brakes and insuring that the towing vehicle shall gently and gradually pick up, the trailer when starting forward. v

Two longitudinal reaches 27 connect the front carriage I9 with the rear carriage 24, and a single forwardly and rearwardly movable unit (see Fig. 8) is formed by said carriages and reaches, the front end of this unit being connected with the tow bar or the like 22 of the towing vehicle while the rear end of said unit is associated with brakeactuating means. In the present disclosure, the reaches '2 Vare connected with the carriages I9 and 24 by means Aof screws 28, the front and rear hollow sections I2 and I4 of the tongue being provided with access plugs 29 (Figs. 3 and 3a.) for said screws. The front and rear .portions of the reaches 21 are received in the hollow front and rear tongue sections I2 and I4, and the intermediate tongue section or cylinder II has longitudinal guideways 30 formed in its Side wall (Figs. 3, 3a and 6) receiving the intermediate portions of said reaches. The outer walls of these guideways 38 may well be formed by detachable plates 134.

A trailer brake master cylinder y32 Vs suitably mounted in :the rear tongue section `I 4 behind the rear carriage 24, andthe piston 33 -cf this master 4cyliruier .is operable .by relative forward .and rearward movements of .said cylinder and .carriage 24. In the present disclosure, the piston 33 is carried by `a rod 34 .secured to Aand projecting rearwardly from the carriage 24, A duid line 35 extends .from the master cylinder 32 to `the -usual cylinders which actuate the brake Shoesat the wheels .of .the .trail-er, .and whenever .the trailer moves forwardly with respect to the towing vehicle (compare Fiss. 1c and 2o.), fluid is forced through the line k35 .to apply the trailer brakes. As the parts return to .normal positions. the brakes .are 4of course released. :Sudden jerking -of the traileru carried and `towi-ng-car-carried `parts vin either brake-applying direction or load pick-up kdirection, is 4prevented by the Shock-.absorbing means including the plunger 26 and the cylinder l?, which means will be hereinafter more specically described.

The rear carriage 24 may be employed as an actuator for mechanical trailer brakes, if desired, ,and .for illustrative purposes, I have illustrated a stud 35 projecting from said carriage through .a Slot 3.1 in the rear tongue section I4 .(see Figs. la and 2c) for connection with suitable brake-.operating connections.

While in Figures l .and la the rear carriage is .shown as having the shock absorber plunger project-.ing from it. ,it is to .benoted that the two carriegos is .and 24 are connected by the reaches A2l' to move .as a unit, and hence it is obvious that the shock absorber plunger may project from either carriage depending whether the shock absorber plunger .is to be pushed or pulled.

Tivo forwardly diverging checks 3.8 are pivotally mounted .at .39 within the front tongue section I2, immediately in advance of .the cylinder ITI,v said checks normally having the retracted positions shown in Fig. 3, but being outwardly projecti-ble into .engagement with checking shoulders on the rear end o1 the front carriage I9, when the towing vehicle and trailer are to be backed. With the checks .38 -abutting the shoulders 40, the trailer tongue cannot slide with respect to the unit .shown in Fig. 8 and consequently there can .be no .brake application during backing of the towing vehicle and trailer. The front portions of the checks 38 are connected with each other by a toggle 4I and this toggle is kconnected with the piston rod 42 of .a cylinder and piston assembly 43 which is mounted in the rear extremity .of the 4of the .small bore 48.

front tongue section I2. Suitable fluid-conducting lines 44 are shown connected with the ends of the assembly 43 and extending forwardly to the towing vehicle. This vehicle is, of course, provided with a suitable valve (not shown) for admitting uid to one end of the assembly 43 and exhausting it from the other end, and vice versa, to thereby move the toggle 4I to either project the @checks .38 :to operative position, for to retract said :checks and hold .them retracted. The .mounting means 45 for the assembly 43 is suitably notched .at 46 to prevent interference with the reaches 2l.

The vshock-absorbing cylinder I'I has a large 'bore 41 at its rear end (Figs. la, 2a and 3a) and a :small :bore 48 at its front end (Figs. l and 1a, Fig. 2, and Figs. 3 and 3a). A huid-conducting passage connects the rear end of the large bore 4l' with the front end of the small bore 48 and is here shown as consisting of a tank 49 suitably mounted upon the cylinder IT, one port 5i! connecting `the rear end of this 'tank with the rear end of .the .bore 4l, and another port 5I connecting the front end of .said tank with the front end The bores 41 and 48 are cooperable with portions of 'theplunger 26, Aas will now be described. Y

The plunger 2B .includes arod '52 secured "to the rear .carriage 24 and extending into the rear bore 4.1 of the cylinder IA'I., through .a stuffing box 53. Secured to .the frontend of this rod .'52 is a piston 54 which is .operable in the large bore 41. Pro- ;iecting forwardly from 'the .piston 54 is a .tubular plunger 55 (Figs. 1, la, .2, 2a, 3 and 3a). The plunger 55 is tubular1 is open at its front end, is loosely slidable in the small bore 48, and is provided wth longitudinal fluid-conducting slots 56, said vslots decreasing .in size and] or number 'from the front .toward the rear of seid plunger 45.

lo This construction gradually checks the forward movement of the piston .54 in the large bore '41 by gradually diminishing the ease with which 'the uid in advance of .said piston may escape and thus there will he .no shock when the towing vehicle picks up the .load of the trailer. It will be noted upon reference to Fig. 3a that the `slot 5B nearest the I.piston 54 terminates short of .said piston, so that the plunger 55 .has a solid or unslotted portion which enters thebore 48 .at the .end of the stroke. That construction effectively prevents any jerk or ,jar when the tow-car starts to pull.V Further .control of the piston movement may :be had vby means of an adjustable plug 51 threaded in the rear end of the tank 49 over the port k5I), which plug may be adjusted `to throttle the ow of fluid from the rear .end of the large bore 47 as .the piston 54 moves rearwardly, preventing the brakes from g1-abbina. I also provide ports `58 .through the ,piston 54, .said ports c having check valves 53 which .open forwardly.

These valves close upon forward movement of the piston `but `.open upon rearward movement of the latter, permitting this rearward movement to occur quickly even though the ports .56 may .be entirely closed, which would otherwise result .in a partial vacuum in front of said piston, with consequent slow starting thereof.

In Figs. 9 land l0, a plunger B0 is Vshown in the .form .of .a .forwardly tapered pin. This plunger may be substituted for the plunger 55, if desired.

The coupling means 20 for connecting the front carriage i9 with the ball -2I .includes complemental, relatively fixed and movable members 6I and 52 in the front end of said Acarriage I5)x .said

members being cooperable with 1each other in forming a socket for said ball 2|. An eccentric 63 is provided to forwardly push the member 62 toward the member 6I, saideccentric being suitably secured to a vertical shaft 64 which is mounted in openings of the carriage I9 for rotation and axial shifting, the upper end of said shaft 64 being provided with a suitable handle 65. The lower end of the eccentric 63 is formed with a groove 66 to receive studs 6l projecting upwardly from the bottom of the carriage I9, when the eccentric is in the operative position shown in Fig. 2, thereby locking said eccentric and consequently holding the coupling means engaged with the ball 2|. A spring 68 exerts a constant downward pressure on the eccentric 63 to hold it in locking engagement with the studs 61, and the only way this eccentric can be released is by pulling upwardly upon the handle 65, whereupon said eccentric may be turned to permit movement of the member S2 to released position. A spring 69 is provided to effect this latter movement of the member 62, and when the eccentric is released (Figs. 1 and 3), the studs 61 limit the rearward movement of the member 62 under the inuence of said spring 69.

Concerning operation of the mechanism, the pull of the towing vehicle is transmitted to the front section I2 of the trailer tongue by the front carriage I9 which normally abuts the end wall I3 of said tongue as seen in Fig. l. When the brakes are applied to the towing vehicle or its speed is otherwise checked, the trailer and its tongue move forwardly with respect to the unit shown in Fig. 8, said unit comprising the front carriage I9, the reaches 21, the rear carriage 24, the plunger 26, the rod 34 and thebrake-applying piston 33. Movable forwardly with the tongue, are the master cylinder 32, the cylinder I1, the chocks 38, and the cylinder assembly 43 connected with said chocks. The forward sliding of the tongue and elements carried thereby with respect to the unit of Fig. 8, is cushioned by the coaction of the cylinder Il with the front portion of the plunger 26 connected with the rear carriage 24, and said cushioned forward movement causes expulsion of fluid from the master cylinder 32 to apply the trailer brakes without any sudden jerk (or to operate mechanical linkage for the same purpose). When the towing vehicle again starts to pull the load, the necessary relative sliding of the parts is again cushioned by the shock-absorbing means so that the load will not be picked up with a jerk. Whenever it is necessary to back the towing vehicle and the trailer, operation of the cylinder and piston assembly 43 is effected, to project the chocks 38 into cooperative relation with the chocking shoulders 40, thus prohibiting such relative movement of the parts as to apply the brakes.

In Figs. 11 and l2, a carriage ISa overlies the rear portion of a towing vehicle '22a and is connected at 29a with said towing vehicle`22a., said carriage being mounted for forward and rearward sliding in the front portion of a house trailer frame ia. Carriage I9a has a lug I9 connected to a plunger 26a corresponding to the plunger 26 above described, said plunger 26a extending into a shock-absorbing cylinder I'Ia secured to the frame Ia over the carriage I9a and corresponding to the above described cylinder I'I. The cylinder Ila, the plunger 26a, and the tank 49a on said cylinder, are constructed like the elements I'I, 26 and 49, above described, and cooperate in the same way. The carriage I9a operates a rod 34a connected with lug I9 to actuate the piston -offthe trailer .brake master cylinder 32a, or me- :chanical brake-applying means may be connected 'trailer frame |60, said carriage I9?) being connected with a subjacent part of the towing vehicle 22h by a king pin or the like Zlib. The carriage I9b operates a plunger 26h and a rod 34h fboth directly connected with said carriage. Plunger 26h coacts with a shock-absorbing unit I1b,49b, like the corresponding units above described, and rod 34h actuates the piston of the ltrailer brake master cylinder 32h. Instead of using rod 34h and cylinder 32h, mechanical brakeactuating means could, of course, be connected `with the carriage |917.

From the foregoing, taken in connection with 'the accompanying drawings, it will be seen that `novel and advantageous provision has been made 'for attaining the desired ends, and while preferences have been disclosed, attention is again in- `vited to the possibility of making variations withinthe scope of the invention as claimed.

I claim:

l. A trailer hitch and brake actuator comprising a hollow trailer tongue having a longitudinal 'slot in its front portion, a forwardly and rearwardly movable member extending longitudinally within said hollow tongue and having supporting 'and guiding rollers contacting with the inner side 'of said tongue, said forwardlyy and rearwardly Amovable member having hitch means exposed at said longitudinal slot for connection with a ball 'on a towing vehicle, a hydraulic brake master cylinder mounted within said hollow tongue behind said forwardly and Arearwardly movable member, a master cylinder plunger secured to said forwardly and. rearwardly movable member and extending rearwardly into said master cylinder, said plunger and the fluid within said master cylinder constituting means for limiting the rearward movement of said forwardly and rearwardly movable member, hydraulic shock-absorbing Ameans within said hollow tongue for checking the forward movement of said forwardly and rearwardly movable member as it nears its extreme forward position, and a stop carried by said tongue to be struck by said forwardly and rearwardly movable member when it reaches said extreme forward position.

2. A trailer hitch and brake actuator comprising a trailer tongue having a front portion, a rear portion, and a shock-absorbing cylinder between said front and rear portions, a front carriage mounted on said front portion of said tongue, a rear carriage mounted on said rear portion of said tongue, a reach connecting said carriages for forward and rearward movement in unison, said shock-absorbing cylinder having a 'guide through which the intermediate portion of said reach extends slidably, means for coupling said front carriage to a towing vehicle, trailer brake actuating means connected with said rear carriage, and a shock-absorbing plunger projecting longitudinally from one of said carriages into said shock-absorbing cylinder.

3. A trailer hitch and brake actuator comprising a trailer tongue having a hollow front portion, a hollow rear portion, and a shock-absorbing cylinder between said hollow front and rear portions, a front carriage mounted in said hollow front portion of said tongue, a rear carriage mounted in said hollow rear portion of said tongue, a 'reach connecting said carriages: for forward and rearward movement in unison, the front and rear portions of said reach being eonned in said hollow front and rear portions of said tongue, the side of said shock-absorbing cylinder having a longitudinal guideway in which the intermed-iate portion of said reach is slidable, means for coupling said front carriage to a towing vehicle, trailer bra-ke actuating means connected with said rear carriage, and a shockabsorbing plunger projecting longitudinally from one of said carriages into said shock-absorbing cylinder.

4. In a trailer hitch and brake actuator including a trailer tongue having a hollow portion, a brake-actuating member longitudinally .slidable `in said hollow portion of said tongue, and means for coupling said member to a towing vehicle; a normally retracted shock mounted in said hollow portion of said tongue for projection into engagement with said member when backing, a cylinder and piston assembly mounted in said hollow portion of said tongue and operatively connected with said chock for projecting and retracting the latter, and means for conducting iiuid to and from said assembly to operate said chock.

5. In a trailer hitch and actuator, relatively slidable members for connection with a trailer and a towing vehicle respectively, one of said members having two laterally spaced checking shoulders, two diverging checks pivotally mounted on the other of said members for outward swinging into engagement with said chocking shoulders when the towing vehicle and trailer are to be backed, a toggle connecting said checks for projecting and retracting them, and operating means connected with said toggle.

6. In a trailer hitch and brake actuator, a trailer including a longitudinal shock-absorbing cylinder having a large bore at its rear end and a small bore at its iront end, Isaid rear end having a stuing box, a forwardly and rearwardly movable brake actuator mounted on the trailer, means for connecting said brake actuator with a towing vehicle, `a piston rod connected with said brake actuator and extending forwardlyV through said stuffing box, a piston on said rod operable said large bore, a plunger projecting forwardly from said piston and operable within said small bore, said plunger being constructed to gradually diminish the flow of fluid from said large bore into said small bore as the piston and plunger move forwardly, and a :duid passage connecting the front end of said small bore with the rear end of said large bore.

'7. In a trailer hitch and brake actuator, a trailer including a longitudinal shock-absorbing cylinder having a large bore at its rear end and a small bore at its front end, said rear .end having a stuiling box, a forwardly and rearwardly movable brake actuator mounted on the trailer, means for connecting said brake actuator with a towing vehicle, a piston rod connected with said brake actuator and extending forwardly through said stuing box, a piston on said rod operable within said large bore, a plunger projecting forwardly from said piston and operable within said small bore, said plunger being tubular, open at `its `front end and longitudinally slotted from its interior to its exterior to gradually diminish the now of fluid from said large bore into said small bore as the piston and plunger move forwardly, and a fluid passage connecting the front end of said small bore with the rear end of said large bore.

8. In a trailer hitch and brake actuator, a trailer including a longitudinal shock-absorbing cylinder having a large bore at its rear end and a. small bore at its front end, said rear end having a stuiiing box, a forwardly and rearwardly movable brake actuator mounted on the trailer, means for connecting said brake actuator with a towing vehicle, a piston rod connected with said brake actuator and extending forwardly through Said stuiing box, a piston on said rod operable within said large bore, a plunger projecting forwardly from said piston and operable within said small bore, said plunger being forwardly tapered to gradually diminish the ow oi fluid from said large bore into said small bore as the piston and plunger move forwarchy, and a fluid passage connecting the front end of said small bore with the rear end of said large bore. v

9. A structure as specied in cl'aim; together with adjustable means for throttling the owof fluid into said large bore to a required extent to control the rearward movement of said piston, and a passage through said piston having a forwardhf opening check valve to permit the piston to quickly move rearwardly when admission of fluid to the fro-nt end of said large bore is momentarily prevented by said plunger.

.10. A trailer hitch and brake actuator comprising a forwardly .and rearwardly movable carriage mounted on the front end of a trailer and adapted to overlie a portion of a towing vehicle, a shockalosorbing lcylinder xedly mounted on the trailer over said carriage, a shock-absorbing plunger .connected with said carriage and operable in said cylinder, means .for .connecting said carriage with .thev subjacent portion .of the trailer, and trailer brake-actuating means operated by said carriage.

.11.. A trailer hitch and brake actuator comprising a carriage to overlie a portion of a towing vehicle, longitudinal trackage on the trailer mounting said carriage for forward and rearward sliding, means for connecting said carriage with the subjacent portion of the towing vehicle, a brake master Cylinder mounted on the trailer behind said carriage,v a shock-absorbing cylinder mounted on the trailer in front of said carriage, a brake-actuating rod extending rearwardly from said carriage into .said master cylinder, and a shock-absorbing plunger extending forwardly from said carriage into said shock-absorbing cylinder.

GURDON SWAIN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,896,427 -Selvester Feb. 7, 1933 2,051,522 Graham Aug. 18, 1936 2,138,267 Christensen Nov. 29, 1938 2,401,084 Laudahl May 28, 1946 

